Clean up DisplayConfigurationController user_action

The parameter |user_action| is passed as true in all the cases.
Therefore remove this parameter.

BUG=none

Review-Url: https://codereview.chromium.org/2726233002
Cr-Commit-Position: refs/heads/master@{#456924}
6 files changed